Re: [Groff] RE: Small bug in groff 1.19.2 footnote number control

[Robert Marks]

On Mon, 17 Sep 2007 at 18:57:06 +0100 Keith Marshall wrote:
>> > So I ask the question of the group:
>> > 
>> >       Do we want to implement "backward compatibility" of
>> >    undocumented things like the number register  :p  in
>> >    the groff package?
>> > 
>> > I vote no.
>
>As do I.
And I (as a mm user these twenty-five years).
>
>> Hmm.  What to do in situations where the `inofficial' way was the only
>> choice?
>
>Exactly as you would in any other situation, where you found it
>necessary to exploit an undocumented feature; go ahead anyway, but
>prominently include a comment in the document, to the effect that:
>
>  .\" This document makes gratuitous use of the undocumented `:p'
>  .\" register, defined by the XYZ implementation of `mm'; it may
>  .\" not be readily portable to other troff implementations.
>  .
>  .\" The equivalent, but also undocumented, feature in groff `mm'
>  .\" is controlled by the `ft*nr' register; thus
>  .
>  .   aln :p ft*nr
>  .
>  .\" should suffice, to allow groff to emulate this undocumented
>  .\" register usage.
>
>Note that it's the `aln' request which is required here, and not `als'
>as suggested in a previous post.
>
I agree with Keith's suggestion for documenting previously undocumentated
features.

For instance, I use the mm macros to number bibliographic items (using
.RL/.LI).  But I wanted to close a list (.LE) and continue the numbering in
the next occurrence of the .RL list, so, after nosing around in the mgm
source, and using nr g to carry the count:

 .nr g \n[li*cnt!\n[li*lvl]]
 .LE
 .sp
 .ne 3
 .ft 3
 Submissions
 .ft 1
 .RL 
 .nr li*cnt!\n[li*lvl] \ng
 .LI

This was definitely different in the DWB mm, but I can't remember now how I
did it then.  

Note that I do not amend the macros: this occurs in my document, but relies
on an undocumented register in mgm.

Robert Marks

-- 
Robert MARKS, Australian Graduate School of Management,
              Australian School of Business, UNSW SYDNEY, NSW 2052,
              Australia
Home page:    <http://www.agsm.edu.au/~bobm>